1/*
2 * Copyright (C) 2012-2017 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include "CellContainer.h"
29#include "WeakBlock.h"
30#include <wtf/SentinelLinkedList.h>
31
32namespace JSC {
33
34class Heap;
35class WeakImpl;
36
37class WeakSet : public BasicRawSentinelNode<WeakSet> {
38 friend class LLIntOffsetsExtractor;
39
40public:
41 static WeakImpl* allocate(JSValue, WeakHandleOwner* = 0, void* context = 0);
42 static void deallocate(WeakImpl*);
43
44 WeakSet(VM*, CellContainer);
45 ~WeakSet();
46 void lastChanceToFinalize();
47
48 CellContainer container() const { return m_container; }
49 void setContainer(CellContainer container) { m_container = container; }
50
51 Heap* heap() const;
52 VM* vm() const;
53
54 bool isEmpty() const;
55 bool isTriviallyDestructible() const;
56
57 void visit(SlotVisitor&);
58
59 void reap();
60 void sweep();
61 void shrink();
62 void resetAllocator();
63
64private:
65 JS_EXPORT_PRIVATE WeakBlock::FreeCell* findAllocator();
66 WeakBlock::FreeCell* tryFindAllocator();
67 WeakBlock::FreeCell* addAllocator();
68 void removeAllocator(WeakBlock*);
69
70 WeakBlock::FreeCell* m_allocator;
71 WeakBlock* m_nextAllocator;
72 DoublyLinkedList<WeakBlock> m_blocks;
73 VM* m_vm;
74 CellContainer m_container;
75};
76
77inline WeakSet::WeakSet(VM* vm, CellContainer container)
78 : m_allocator(0)
79 , m_nextAllocator(0)
80 , m_vm(vm)
81 , m_container(container)
82{
83}
84
85inline VM* WeakSet::vm() const
86{
87 return m_vm;
88}
89
90inline bool WeakSet::isEmpty() const
91{
92 for (WeakBlock* block = m_blocks.head(); block; block = block->next()) {
93 if (!block->isEmpty())
94 return false;
95 }
96
97 return true;
98}
99
100inline bool WeakSet::isTriviallyDestructible() const
101{
102 if (!m_blocks.isEmpty())
103 return false;
104 if (isOnList())
105 return false;
106 return true;
107}
108
109inline void WeakSet::deallocate(WeakImpl* weakImpl)
110{
111 weakImpl->setState(WeakImpl::Deallocated);
112}
113
114inline void WeakSet::lastChanceToFinalize()
115{
116 for (WeakBlock* block = m_blocks.head(); block; block = block->next())
117 block->lastChanceToFinalize();
118}
119
120inline void WeakSet::visit(SlotVisitor& visitor)
121{
122 for (WeakBlock* block = m_blocks.head(); block; block = block->next())
123 block->visit(visitor);
124}
125
126inline void WeakSet::reap()
127{
128 for (WeakBlock* block = m_blocks.head(); block; block = block->next())
129 block->reap();
130}
131
132inline void WeakSet::resetAllocator()
133{
134 m_allocator = 0;
135 m_nextAllocator = m_blocks.head();
136}
137
138} // namespace JSC
139